This invention relates to a reinforced fitting construction and, more particularly, pertains to a fitting body of cured resin and reinforcing glass filaments having embedded therein a reinforcing rigid cage of metal straps. The provided fitting construction possesses excellent corrosion resistance and strength, enabling the same to be particularly adapted for use in industries where corrosive conditions are encountered such as in the oil and chemical industries.
The art relating to fitting manufacture is cognizant of the desirability of fabricating fittings of corrosion-resistant materials such as glass filaments and cured resins as disclosed in patents such as Thomas U.S. Pat. No. 3,765,979 granted Oct. 16, 1973. Similarly, the prior art is aware of the desirability of employing encircling metal reinforcements over fittings and the like as evidenced by teachings such as Murray U.S. Pat. No. 1,696,725 granted Dec. 25, 1928 which discloses fittings having metal reinforcements secured about the exterior surfaces thereof. However, there is nowhere shown or suggested in the prior art the desirability of employing a glass reinforced resin fitting of superior corrosion resistance having embedded therein a reinforcing metal cage which imparts superior strength to the fitting having the same disposed thereover. Since fittings comprise tubular portions arranged along intersecting axes, intersecting forces are normally exerted on such tubular portions in the normal course of fitting use. Such forces necessitate an ability of the fitting body to resist shear, tensile and torsion forces if failure is to be avoided.
It is an object of this invention, therefore, to provide a fitting construction of superior corrosion resistance and strength heretofore unattainable by fittings of the prior art.
It is another object of this invention to provide a method of fitting manufacture in which a steel reinforcing cage is intimately united to and locked within an encapsulating glass-resin matrix. The cage is embedded in and mechanically locked to the matrix in the absence of voids in the fitting body, which voids give rise to areas of weakness.
It is a further object of this invention to provide a novel fitting construction in which the threads formed therein are of exceptional strength by virtue of their location adjacent a steel reinforcement and resulting exceptional resistance to shear forces.
It is still a further object of this invention to provide a novel fitting construction comprising a minimum number of materials of fabrication which may be efficiently manufactured on a commercial basis.
It is yet another object of this invention to provide a method of forming fitting constructions which comprises a minimum number of basic process steps and manufacturing apparatus of relatively simple design.